Systems, Devices, and Methods for Robotic End Effectors

ABSTRACT

A robotic end effector or end-of-arm tool may take the form of a mechanical digit (e.g., mechanical finger), or employ one or more mechanical digits (e.g., mechanical fingers), controllable in multiple degrees of freedom, e.g., pitch, yaw, curl. The mechanical digit(s) advantageously comprise a skeleton and three (3) piston/cylinders combinations, one controlling curl, and the other two controlling pitch and/or yaw. Mechanical digits may comprises a number of rolling contact joints. A flexible printed circuit board (PCB) carrying a variety of sensors covers the skeleton, and runs inside the rolling contact joints to provide a zero length change path. Knuckle imitators may cause a membrane cast or sheath joint to resemble human knuckles.

TECHNICAL FIELD

The present systems, devices, and methods are generally related torobotics and more particularly to robot end effectors or end-of-armtools and/or actuators, for example mechanical hands or mechanical handswith mechanical digits having multiple degrees of freedom.

BACKGROUND

Robots or robotic appendages typically employ an end-of-arm tool or endeffector to interact with objects in an environment in which the robotoperates. Some end-of-arm tools or end effectors are relatively simplearticles, without moving elements (e.g., push bar, hook, suction cup)allowing simple interactions or engagement (e.g., push, pull, lift) withobjects in the environment. Other end-of-arm tools or end effectors arerelatively complex machines, with moving elements (e.g., grippers,digits) allowing complex interactions or engagement (e.g., grasping)with objects in the environment.

As the field of robots develops, more sophisticated and/or robustend-of-arm tools or end effectors are desirable.

SUMMARY

Described and illustrated herein are robot end effectors, end-of-armtools and/or actuators that take the form of a mechanical digit (e.g.,mechanical finger), or employ one or more mechanical digits (e.g.,mechanical fingers), that can be controlled in three (3) degrees offreedom (pitch and yaw of a first (1^(st)) joint, and combined curl of asecond (2^(nd)) joint and a third (3^(rd)) joint). The mechanicaldigit(s) advantageously comprise a skeleton and three (3) pistons andassociated cylinders, one controlling the curl, and the other twocontrolling the pitch and/or yaw. One or more valves fluidly couple oneor more sources of pressurized fluid (e.g., liquid for instancehydraulic fluid; gas for instance air) to the cylinders and are operableto control a pressure on one or both sides of the piston in therespective cylinder to cause the piston to translate with respect to therespective cylinder to set the position of the pistons to obtain adesired or directed amount of rotation about a curl axis, rotation abouta pitch axis and/or rotation about a yaw axis. The pistons and cylindersmay take the form of hydraulic piston and cylinder combinations, oralternatively take the form of pneumatic piston and cylindercombinations.

Each joint of the mechanical digit may advantageously be comprised ortake the form of a rolling contact joint. There may also be a singlesheet of flexible printed circuit board (PCB) carrying a variety ofsensors that covers an outer surface of the skeleton, the flexible PCBadvantageously running inside of the rolling contact joint (whichprovides a zero length change path for the flexible PCB through a fullrange of motion).

All three pistons and cylinders may be located in a base of themechanical digit, or alternatively in a palm to which the mechanicaldigit is coupled. The curl degree of freedom may be transmitted througha set of gears and linkages. The skeleton may also include two knuckleimitators, each located at a respective one of the curl joints, andwhich extend past the curl joints to provide a shape similar to a humanfinger knuckle when a flexible, resilient skin (e.g., silicone membrane)is cast around the skeleton or when a silicone skin glove or sheath isplaced around the skeleton.

A robotic end effector may be summarized as including: a firstmechanical digit comprising: a first base; a first phalanx; a firstrolling surface joint that rotationally mechanically couples the firstphalanx to the base for rotation about a pitch axis and rotation about ayaw axis; a second phalanx; a second rolling surface joint thatrotationally mechanically couples the second phalanx to the firstphalanx for rotation about a first curl axis; a third phalanx; and athird rolling surface joint that rotationally mechanically couples thethird phalanx to the second phalanx for rotation about a second curlaxis; a first cylinder; a first piston slideably received by the firstcylinder for translation along a first translation axis; a first linkagethat mechanically couples the first piston with the first phalanx at aposition laterally spaced on a first side of a centerline of the firstphalanx; a second cylinder; a second piston slideably received by thesecond cylinder for translation along a second translation axis; asecond linkage that mechanically couples the second piston with thefirst phalanx at a position laterally spaced on a second side of thecenterline of the first phalanx; a third cylinder; a third pistonslideably received by the third cylinder for translation along a thirdtranslation axis; and a third linkage that mechanically couples thethird piston with the second and the third phalanges, wherein therotation about the pitch axis is controllably actuated or caused bymovement of both the first piston along the first translation axis andthe second piston along the second translation axis, the rotation aboutthe yaw axis is controllably actuated or caused by movement of one orboth of the first piston along the first translation axis and the secondpiston along the second translation axis, and the rotation about thefirst and the second curl axes is controllably actuated or caused bymovement of the third piston along the third translation axis.

A rotation about the yaw axis without rotation about the pitch axis maybe controllably actuated or caused by concurrent movements of the firstpiston along the first translation axis and the second piston along thesecond translation axis that are equal in speed and magnitude butopposite in direction with respect to one another along the respectivefirst and second translation axes. A rotation about the pitch axiswithout rotation about the yaw axis may be controllably actuated orcaused by concurrent movements of the first piston along the firsttranslation axis and the second piston along the second translation axisthat are equal in speed, magnitude and direction with respect to oneanother along the respective first and second translation axes. Arotation about the yaw axis with a rotation about the pitch axis may becontrollably actuated or caused by movements of the first piston alongthe first translation axis and the second piston along the secondtranslation axis that are at least one of: not concurrent, not matchedin speed, or not matched in magnitude, along the respective first andsecond translation axes.

The second translation axis may be parallel to the first translationaxis, and the yaw axis may be perpendicular to a plane in which thefirst and the second translation axes lie.

The first linkage may comprise a first piston rod having a first end anda second end, the first end of the first piston rod coupled to the firstpiston to rotate about two axes that are orthogonal to the firsttranslation axis, and the second linkage may comprise a second pistonrod having a first end and a second end, the first end of the secondpiston rod coupled to the second piston to rotate about two axes thatare orthogonal to the second translation axis.

The first end of the first piston rod may comprise a first ball jointthat is directly coupled to the first piston to rotate about the twoaxes that are orthogonal to the first translation axis, and the firstend of the second piston rod may comprise a second ball joint that isdirectly coupled to the second piston to rotate about the two axes thatare orthogonal to the second translation axis. The second end of thefirst piston rod may be coupled to the first phalanx to rotate about twoaxes that are orthogonal to the first phalanx, and the second end of thesecond piston rod may be coupled to the first phalanx to rotate abouttwo axes that are orthogonal to the first phalanx. The robotic endeffector may further include: a first spring positioned to bias thefirst piston toward a first piston position in the first cylinder; afirst valve positioned and operable to selectively open and close afirst fluidly communicative path between a portion of an interior of thefirst cylinder and a source of a pressurized fluid; a second springpositioned to bias the second piston toward a second piston position inthe second cylinder; and a second valve positioned and operable toselectively open and close a second fluidly communicative path between aportion of an interior of the second cylinder and a source of apressurized fluid.

The third linkage may include a third piston rod, a first set of gearscoupled between the first base and the first phalanx, a second set ofgears coupled between the first phalanx and the second phalanx, and athird set of gears coupled between the second phalanx and the thirdphalanx. The third piston rod may have a first end and a second end, thefirst end of the third piston rod coupled to the third piston totranslate therewith, and the second end of the third piston rodrotatably coupled to at least one gear of the first set of gears, atleast one of the gears of the first set of gears coupled to at least oneof the gears of the second set of gears, and at least one of the gearsof the second set of gears coupled to at least one gear of the third setof gears to transfer translational movement of the third piston rod intorotational movement of the second and the third phalanges about thefirst and the second curl axes, respectively. The third linkage mayfurther include a plurality of bar links that couple at least one gearfrom the first set of gears to at least one gear of the second set ofgears and that couple at least one gear from the second set of gears toat least one gear of the third set of gears. The first end of the thirdpiston rod may include a ball joint that is directly coupled to thethird piston to rotate about two axes that are orthogonal to the thirdtranslation axis. The second end of the third piston rod may be coupledto rotate about an axis that is parallel to the pitch axis and to rotateabout an axis that is parallel to the yaw axis. The robotic end effectormay further include: a third spring positioned to bias the third pistontoward a third piston position in the third cylinder; and a third valvepositioned and operable to selectively open and close a third fluidlycommunicative path between a portion of an interior of the thirdcylinder and a source of a pressurized fluid.

The robotic end effector may further include a flexible printed circuitboard that extends between the first base and the third phalanx andwhich wraps partially about each of the first rolling surface joint, thesecond rolling surface joint, and the third rolling surface joint. Thefirst rolling surface joint may include a first rolling surface of thefirst base and a second rolling surface of the first phalanx. Theflexible printed surface board may extend over the first rolling surfaceof the first base and the second rolling surface of the first phalanx.Respective surface curvatures of the first rolling surface of the firstbase and the second rolling surface of the first phalanx may berespectively shaped relative to the pitch axis to ensure there is nolength change in a path of the flexible printed circuit board when thefirst phalanx transitions into and between a neutral pose, a pitched-uppose, and a pitched-down pose.

The first cylinder, the second cylinder, and the third cylinder may allbe formed in the first base. The first base may comprise a fluidmanifold including: a volume that contains at least respective portionsof each of the first cylinder, the second cylinder, and the thirdcylinder; a first valve positioned and operable to selectively open andclose a first fluidly communicative path between a portion of aninterior of the first cylinder and a source of a pressurized fluid; asecond valve positioned and operable to selectively open and close asecond fluidly communicative path between a portion of an interior ofthe second cylinder and a source of a pressurized fluid; and a thirdvalve positioned and operable to selectively open and close a thirdfluidly communicative path between a portion of an interior of the thirdcylinder and a source of a pressurized fluid.

The robotic end effector may further include a palm, wherein the firstbase is mechanically coupled to or part of the palm; and a secondmechanical digit comprising: a second base mechanically coupled to orpart of the palm; a fourth phalanx; a fourth rolling surface joint thatrotationally mechanically couples the fourth phalanx to the second basefor rotation about a pitch axis and rotation about a yaw axis; a fifthphalanx; a fifth rolling surface joint that rotationally mechanicallycouples the fifth phalanx to the fourth phalanx for rotation about athird curl axis; a sixth phalanx; and a sixth rolling surface joint thatrotationally mechanically couples the sixth phalanx to the fifth phalanxfor rotation about a fourth curl axis; a fourth cylinder; a fourthpiston slideably received by the fourth cylinder for translation along afourth translation axis; a fourth linkage that mechanically couples thefourth piston with the fourth phalanx at a position laterally spaced ona first side of a centerline of the fourth phalanx; a fifth cylinder; afifth piston slideably received by the fifth cylinder for translationalong a fifth translation axis; a fifth linkage that mechanicallycouples the fifth piston with the fourth phalanx at a position laterallyspaced on a second side of the centerline of the fourth phalanx; a sixthcylinder; a sixth piston slideably received by the sixth cylinder fortranslation along a sixth translation axis; and a sixth linkage thatmechanically couples the sixth piston with the fifth phalanx and thesixth phalanx, wherein the rotation about the pitch axis is caused bymovement of both the fourth piston along the fourth translation axis andthe fifth piston along the fifth translation axis, the rotation aboutthe yaw axis is caused by movement of one or both of the fourth pistonalong the fourth translation axis and fifth piston along the fifthtranslation axis, and rotation about the third and the fourth curl axesis caused by movement of the sixth piston along the sixth translationaxis.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elementsor acts. The sizes and relative states of elements in the drawings arenot necessarily drawn to scale. For example, the positions of variouselements and angles are not drawn to scale, and some of these elementsare arbitrarily enlarged and positioned to improve drawing legibility.Further, the particular shapes of the elements as drawn are not intendedto convey any information regarding the actual shape of the particularelements, and have been solely selected for ease of recognition in thedrawings.

FIG. 1 is a front, top, left side isometric view of a robotic mechanicaldigit in a straight or neutral pose and without a membrane or artificialskin, according to the present systems, devices, and methods.

FIG. 2 is a rear, bottom, right side isometric view of the roboticmechanical digit of FIG. 1 in the straight or neutral pose, according tothe present systems, devices, and methods.

FIG. 3 is a top, rear, left side isometric view of a robotic mechanicaldigit of FIG. 1 in a full curl and pitch down pose, according to thepresent systems, devices, and methods.

FIG. 4A is a top plan view of the robotic mechanical digit of FIG. 1 inthe straight or neutral pose, according to the present systems, devices,and methods.

FIG. 4B is a left side elevational view of the robotic mechanical digitof FIG. 1 in the straight or neutral pose, according to the presentsystems, devices, and methods.

FIG. 5A is a cross-sectional view of the robotic mechanical digit ofFIG. 1 in the straight or neutral pose taken along a first plane 402(FIG. 4A), according to the present systems, devices, and methods.

FIG. 5B is a cross-sectional view of the robotic mechanical digit ofFIG. 1 in the straight or neutral pose, the section taken along a secondplane 404 (FIG. 4A), according to the present systems, devices, andmethods.

FIG. 5C is a cross-sectional view of the robotic mechanical digit ofFIG. 1 in the straight or neutral pose, the section along a third plane406 (FIG. 4A), according to the present systems, devices, and methods.

FIG. 5D is a cross-sectional view of the robotic mechanical digit ofFIG. 1 in the straight or neutral pose, the section along a fourth plane408 (FIG. 4A), according to the present systems, devices, and methods.

FIG. 6 is a cross-sectional view of the robotic mechanical digit of FIG.1 in the fully curled, pitch-down pose, the section along the fourthplane 408 (FIG. 4A), according to the present systems, devices, andmethods.

FIG. 7 is a cross-sectional view of a portion of the robotic mechanicaldigit of FIG. 1 in the straight or neutral pose taken along a sixthplane 412 (FIG. 4B), according to the present systems, devices, andmethods.

FIG. 8 is a cross-sectional view of a portion of the robotic mechanicaldigit of FIG. 1 in a pose with a rotation counterclockwise about a yawaxis, the section taken along a sixth plane 412 (FIG. 4B), according tothe present systems, devices, and methods.

FIG. 9A is a cross-sectional view of a portion of the robotic mechanicaldigit of FIG. 1 in a straight or neutral pose, the section taken along afifth plane, according to the present systems, devices, and methods.

FIG. 9B is a cross-sectional view of a portion of the robotic mechanicaldigit of FIG. 1 in a pitched-up pose rotated counterclockwise about apitch axis, the section taken along the fifth plane, according to thepresent systems, devices, and methods.

FIG. 9C is a cross-sectional view of a portion of the robotic mechanicaldigit of FIG. 1 in a pitched-down pose rotated clockwise about the pitchaxis, the section taken along the fifth plane, according to the presentsystems, devices, and methods.

FIG. 10A is a front, top, right side isometric view of the roboticmechanical digit of FIG. 1 with a flexible printed circuit board (PCB)omitted to better illustrate various joints, according to the presentsystems, devices, and methods.

FIG. 10B is a plan view of a first side of a flexible printed circuitboard (PCB) of the robotic mechanical digit of FIG. 1, the flexible PCBillustrated in a flattened configuration, according to the presentsystems, devices, and methods.

FIG. 10C is a plan view of a second side of a flexible printed circuitboard (PCB) of the robotic mechanical digit of FIG. 1, the second sideopposite the first side across a thickness of the flexible PCB, theflexible PCB illustrated in a flattened configuration, according to thepresent systems, devices, and methods.

FIG. 11A is a top, left side, rear isometric view of the roboticmechanical digit of FIG. 1 in a pitched-down pose rotatedcounterclockwise about a pitch axis and actuated by an outward extensionof both a right piston and a left piston, according to the presentsystems, devices, and methods.

FIG. 11B is a top, left side, rear isometric view of the roboticmechanical digit of FIG. 1 in a pitched-up pose rotated clockwise aboutthe pitch axis and actuated by an inward retraction of both the rightpiston and the left piston, according to the present systems, devices,and methods.

FIG. 12A is a top, left side, rear isometric view of the roboticmechanical digit of FIG. 1 in a yaw-right pose rotated clockwise about ayaw axis and actuated by an outward extension of the left piston and aninward retraction of the right piston, according to the present systems,devices, and methods.

FIG. 12B is a top, left side, rear isometric view of the roboticmechanical digit of FIG. 1 in a yaw-left pose rotated counterclockwiseabout the yaw axis and actuated by an outward extension of the rightpiston and an inward retraction of the left piston, according to thepresent systems, devices, and methods.

FIG. 12C is a top, left side, rear isometric view of the roboticmechanical digit of FIG. 1 in a curled pose rotated counterclockwiseabout one or more curl axes and actuated by an outward extension of athird piston, according to the present systems, devices, and methods.

FIG. 13A is a front, bottom, left side isometric view of a portion ofthe robotic mechanical digit of FIG. 1, according to the presentsystems, devices, and methods.

FIG. 13B is a front, top, left side isometric view of the portion of arobotic mechanical digit of FIG. 1, according to the present systems,devices, and methods.

FIG. 14 is a top plan view of a robotic end effector comprising a handwith a palm and a plurality of mechanical digits that include fourmechanical fingers and a mechanical thumb, according to the presentsystems, devices, and methods.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various disclosedimplementations and embodiments. However, one skilled in the relevantart will recognize that implementations and embodiments may be practicedwithout one or more of these specific details, or with other methods,components, materials, etc. In other instances, certain structuresassociated with robots, robotic appendages, linkages, valves, cables oractuators, reservoirs of pressurized fluid (e.g., liquid, gas), and/orcompressors, have not been shown or described in detail to avoidunnecessarily obscuring descriptions of the implementations orembodiments.

Unless the context requires otherwise, throughout the specification andclaims which follow, the word “comprise” and variations thereof, suchas, “comprises” and “comprising” are to be construed in an open,inclusive sense, that is, as “including, but not limited to.”

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrases “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.Furthermore, the particular features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

The headings and Abstract of the Disclosure provided herein are forconvenience only and do not interpret the scope or meaning of theembodiments.

FIGS. 1, 2 and 3 show an example of a robotic mechanical digit 100,according to the present systems, devices, and methods. In particular,FIG. 1 shows a front, top, left side isometric view of roboticmechanical digit 100 in a straight or neutral pose and without anymembrane or artificial skin, which may be included in someimplementations; FIG. 2 shows a rear, bottom, right side isometric viewof robotic mechanical digit 100 in the straight or neutral pose andwithout any membrane or artificial skin; and FIG. 3 shows a top, rear,left side isometric view of robotic mechanical digit 100 in a full curland pitch down pose, according to the present systems, devices, andmethods.

Robotic mechanical digit 100 comprises skeleton that includes a base102. The base 102 may have one or more mechanical coupling or attachmentpoints or features that allow attachment to a palm or similar roboticstructure, which may or may not be analogous to a human hand. The base102 includes a right cylinder 104 a and a left cylinder 104 b, where“right” and “left” respectively correspond to first and second lateralsides of a centerline that passes longitudinally through mechanicaldigit (i.e., though base 102, first phalanx 112, second phalanx 114, andthird phalanx 114) along the y-axis of FIG. 1. A right piston rod 106 aand a left piston rod 106 b are partially within, and extend outwardlyfrom, the left and right cylinders 104 a and 104 b respectively. Coupledto a second end of the right piston rod 106 a is a right pitch-yawlinkage 108 a, and coupled to a second end of the left piston 106 b is aleft pitch-yaw linkage 108 b. Additional details of the inside of theleft and right cylinders and their couplings are visible in FIGS. 6, 7,and 9. The right and left pitch-yaw linkages 108 a, 108 b are rotatablycoupled to opposite sides of a yaw carriage 110 which is rotatablycoupled around a z-axis to a bottom plate 111 which is fixed to the base102. Also rotatably coupled to the right and left pitch-yaw linkages 108a, 108 b is the first phalanx 112 at a first end of the first phalanx112. Also rotatably coupled near the first end of the first phalanx 112is the yaw carriage 110 by a first rolling surface joint 113. Additionaldetails of the pitch-yaw linkages 108 a, 108 b and yaw carriagecouplings and their locations are visible in FIGS. 3 and 9. The firstphalanx 112 is coupled at a second end to a first end of a secondphalanx 114 by a second rolling surface joint 115 as illustrated inFIGS. 5A-5D. Similarly, the second phalanx 114 is coupled at a secondend thereof to a first end of a third phalanx 116 by a third rollingsurface joint 117. The first, second, and third phalanges 112, 114, 116,and their rolling surface joints 113, 115, and 117 (respectively), areillustrated in FIGS. 5A-5D and 6. Woven into the rolling surface jointsand coupled to the phalanges is a first flexible printed circuit board(flexPCB) 118 which, in this implementation, is electrically andmechanically coupled to the yaw carriage 110 (as visible in FIGS. 13Aand 13B) and then woven through the rolling surface joints 113, 115, and117 of the phalanges 112, 114, and 116, and fixed to the third phalanx116 (as visible in FIGS. 5A-5D). The first flexPCB 118 also comprises aset of folding faces that cover the sides of the phalanges 112, 114, and116. More details of the first flexPCB 118, the path of the firstflexPCB 118, and the mechanical and electrical couplings of the firstflexPCB 118 are visible in FIGS. 5A, 9A, 9B, 9C, 10B, and 10C. The firstflexPCB 118 may also include or electrically couple to a set of tactilesensors, which are not illustrated in FIGS. 1, 2 and 3 but areillustrated in FIGS. 10B and 10C. Finally, a bottom cylinder 120 sitswithin the base (more detail visible in FIG. 6).

As illustrated in FIG. 2, an electrical connector port 202 may beprovided that electrically connects to flexPCB 118 and allows flexPCB118 to be electrically coupled to a palm or similar robotic structure.The electrical connector port 202 is held in place by a retaining piece204 fixed to the bottom plate 111 to which the yaw carriage 110 isrotatably coupled at pin joint 206. Furthermore, in the illustratedimplementation base 102 comprises a fluid manifold (e.g., a hydraulicmanifold) including a volume that contains at least respective portionsof the right cylinder 104 a, the left cylinder 104 b, and the bottomcylinder 120 and fluid ports and/or valves for the three cylinders: abottom cylinder fluid port 208 that provides a fluidly communicativepath from a source of pressurized fluid (e.g., hydraulic or pneumaticfluid) to bottom cylinder 120 (FIG. 6), a right cylinder fluid port 210a that provides a fluidly communicative path from a source ofpressurized fluid (which may be the same source of pressurized fluidthat is fluidly communicatively coupled to bottom cylinder 120 by port208, or which may be a separate source of pressurized fluid) to rightcylinder 104 a (FIG. 7), and a left cylinder fluid port 210 b thatprovides a fluidly communicative path from a source (again, a samesource or a different source) of pressurized fluid to left cylinder 104b (FIG. 7). One or more hydraulic or pneumatic fluid conduit(s) may becoupled to the fluid ports 208, 210 a, 210 b in order to supply varyingpressures of a hydraulic or pneumatic fluid to control a position ofpistons within the respective cylinders 120, 104 a, 104 b.

As noted above, FIG. 3 shows the robotic mechanical digit 100 in a fullcurl and pitch down pose 300. FIG. 3 also clearly shows a rightspherical or ball joint 304 a coupling the right piston rod 106 a to theright pitch-yaw linkage 108 a and a left spherical or ball joint 304 bcoupling the left piston rod 106 b to the left pitch-yaw linkage 108 b.Right spherical or ball joint 304 a is directly attached to right pistonrod 106 a and left spherical or ball joint 304 b is directly attached toleft piston rod 106 b. Also visible due to the curled pose are a firstknuckle 306 a and a second knuckle 306 b, both of which protrude inorder to, when covered by a stretchable artificial skin layer, simulatethe external shape of a human knuckle bone. More details of themechanics of the first and second knuckles 306 a, 306 b are illustratedin FIG. 5C, FIG. 5D, and FIG. 6.

In FIG. 3, robotic mechanical digit 100 is in a fully pitched down pose,meaning that the first phalanx 112 has pitched forward (e.g.,counterclockwise around a “pitch axis” or x-axis in the view of FIG. 3)such that its longitudinal axis points in a direction of a z-axis. Thisis caused by a simultaneous actuation of a right and left piston 106 a,106 b sitting within the right and left cylinders 104 a, 104 b. Thisaction is further illustrated in FIGS. 9A, 9B, and 9C. Similarly, thecurling of the second and third phalanges 114, 116 in this pose is dueto the actuation of a bottom piston 604 within the bottom cylinder 120as illustrated in FIG. 6.

FIG. 4A shows robotic mechanical digit 100 in the straight or neutralpose. Shown by broken lines are a first plane 402, a second plane 404, athird plane 406, and a fourth plane 408, all parallel to a yz-plane. Theplanes 402, 404, 406, and 408 are at different depths from the left side(per the view of FIG. 4A) of robotic mechanical digit 100 and a leftsection view at each of planes 402, 404, 406, and 408 is shown in FIGS.5A, 5B, 5C, and 5D, respectively. The fourth plane 408 is positioned atthe center of mechanical digit 100 and a left section view at this planeis also shown in FIG. 6. Similarly, a fifth plane 410 is shown by abroken line, and is also parallel to the yz-plane. The fifth plane 410is positioned such that a center of the left cylinder 104 b sits on saidplane. A left section view at the fifth plane 410 is shown in FIGS. 9A,9B, and 9C.

FIG. 4B shows robotic mechanical digit 100 in the straight or neutralpose. Shown by a broken line is a sixth plane 412 parallel to theyx-plane and positioned such that respective centers of both the rightcylinder 104 a and left cylinder 104 b are on the sixth plane 412. Crosssectional views at the sixth plane 412 are shown in FIGS. 7 and 8.

FIGS. 5A, 5B, 5C, and 5D show robotic mechanical digit 100 with sectioncuts at planes 402, 404, 406, and 408 respectively. Visible in FIGS. 5A,5B, 5C, and 5D are a set of rolling surfaces 501 a, 501 b, 501 c, 501 d,501 e, 501 f (collectively either 501 a-501 f or 501), a first phalanxbody 502, a second phalanx body 504, and a third phalanx body 506, a setof phalangeal gears 507 a, 507 b, 507 c, 507 d, 507 e, 507 f(collectively either 507 a-507 f or 507), a first phalanx link 508, asecond phalanx link 510, a first curl link 511, a second curl link 512,a set of pin joints 514 a-j, a first curl gear 516 a, and a second curlgear 516 b. Each of the phalanx bodies 502, 504, and 506, the links 508,510, 511, and 512, and each of the gears 516 a and 516 b is symmetricalacross the yz-plane, and all features and connections described in FIGS.5A, 5B, 5C, and 5D are also present on a right side of mechanical digit100.

As visible in FIG. 5A, the flexPCB 118 (illustrated in FIGS. 5A, 5B, 5C,and 5D with a thick black line; for a planar view of the unfolded PCB,see FIGS. 10B and 10C) is coupled to the yaw carrier 110 at one end,threads between rolling surfaces 501 a and 501 b to a top of the firstphalanx body 502, threads between rolling surfaces 501 c and 501 d to abottom of the second phalanx body 504, threads between rolling surfaces501 e and 501 f to a top of the third phalanx body 506, wraps around atip of the third phalanx body 506 and is fixed to the third phalanx body506 at a bottom thereof. The rolling surfaces 501 a and 501 b form thefirst rolling surface joint 113, the rolling surfaces 501 c and 501 dform the second rolling surface joint 115, and rolling surfaces 501 eand 501 f form the third rolling surface joint 117. The flexPCB 118 alsoincludes paneling or wings that wraps or wrap around the sides of thefirst, second, and third phalanges. The paneling or wings areillustrated in FIGS. 10B and 10C.

The pin joint 514 a rotatably couples together the right and leftpitch-yaw linkages 108 a, 108 b, the first curl gear 516 a, and the yawcarriage 110. The pin joint 514 b rotatably couples together the rightand left pitch-yaw linkages 108 a, 108 b, the second curl gear 516 b,and the first phalanx body 502. The pin joint 514 c rotatably couplestogether the second curl gear 516 b and the first phalanx link 508. Thepin joint 514 d rotatably couples together the first curl link 511 andthe first phalanx link 508. The pin joint 514 e rotatably couplestogether the first curl link 511 and the first phalanx body 502. The pinjoint 514 f rotatably couples together the second phalanx link 510 andthe first curl link 511. The pin joint 514 g rotatably couples togetherthe second phalanx body 504 and the first curl link 511. The pin joint514 h rotatably couples together the second phalanx link 510 and thesecond curl link 512. The pin joint 514 i rotatably couples together thesecond phalanx body 504 and the second curl link 512. The pin joint 514j rotatably couples together the third phalanx body 506 and the secondcurl link 512.

The rolling surfaces 501 a, 501 b, 501 c, 501 d, 501 e, and 501 f eachhave respective profiles defined by arcs centered on pin joints 514 a,514 b, 514 e, 514 g, 514 i, and 514 j respectively. Rolling surfaces 501a and 501 b, rolling surfaces 501 c and 501 d, and rolling surfaces 501e and 501 f, form respective pairs of rolling surfaces having, forexample, equal radii. In the illustrated implementations, the radii areequal to half of the distance between their centers less a thickness ofthe flexPCB 118 such that, with the flexPCB 118 between them, therolling surfaces can roll against one another without slippage or achange in length of the flexPCB 118. Spaced inwardly from each of therolling surfaces 501 a-501 f is a respective phalangeal gear 507 a-507 fcentered at a respective pin joint. Phalangeal gears 507 a and 507 b,507 c and 507 d, and 507 e and 507 f form respective pairs of gearshaving, for example, equal pitch circle radii and pitches, and each pairof gears is engaged with one another. Similarly, the first curl gear 516a and the second curl gear 516 b have, for example, equal pitch circleradii and pitches, and are engaged with one another. Due to all of theabove mechanical couplings, when the first curl gear is actuated suchthat it rotates clockwise (from the point of view of the left sectionview of FIGS. 5A, 5B, 5C, and 5D), the linkage created by the variety oflinks and gears curls the second and third phalange bodies 504, 506counterclockwise around the x-axis. This actuation is functionalregardless of the pitch of the first phalanx body 502 (as visible inFIGS. 9A, 9B, and 9C) due to the freedom of the second curl gear 516 bto orbit around the first curl gear 516 a without rotating relative tothe first phalanx body 502.

FIG. 6 shows a sectional view along fourth plane 408 from FIG. 4A ofrobotic mechanical digit 100 in a fully curled, pitch-down pose. Visiblein FIG. 6 are a back of the bottom cylinder 602, a bottom piston 604slideably received by the bottom cylinder 602 for translation along atranslation axis, and a set of O-Ring seals 606. Also shown are a bottompiston rod 608 directly coupled at a first end to the bottom piston 604by a first spherical or ball joint 610 a and at a second end to thefirst curl gear 509 a by a second spherical or ball joint 610 b, aspring 612 which sits within the bottom cylinder 120 and pushes on thebottom piston 604, and a bleed port 614. Illustrated as a dark arrow isthe movement of a hydraulic fluid 616 (e.g., an oil, such as mineral oilor peanut oil) from an external source through the bottom port 208 intoa back of the bottom cylinder 602. This fluid movement 616 applies apressure on the bottom piston 604 and, assuming the pressure is greaterthan that applied by the spring 612 causes the bottom piston 604 to movewithin the bottom cylinder 120, pushing the bottom piston rod 608forwards, causing the first curl gear 509 a to rotate around its pinjoint 514 a, and actuating the rest of the curl mechanism as describedabove. When the movement of the fluid 616 is relieved, reversed, orotherwise changed, the force applied by the spring 612 may be sufficientto move the bottom piston 604 backwards into the cylinder 120, causingthe curl mechanism to reverse. This reversed movement straightens thesecond and third phalanges 504, 506 with respect to the first phalanx502. Due to the spherical or ball joints 610 a, 610 b at bothconnections of the bottom piston rod 608, this actuation is capable ofproceeding regardless of the rotation of the yaw carriage 110 around thez-axis. While illustrated using a spring 612, some implementations mayhave ports to provide pressurized fluid at both a front and the back ofthe bottom cylinder 120, allowing omission of the spring 612, butsomewhat complicating the overall structure and operation. The ports(e.g., 208, 614) may each have one or more valves associated therewith,for instance active valves that can be operated to selectively pass orblock a passage of fluid therethrough, and/or passive valves, forinstance check valves. The valve(s) may be positioned at the port(s) orremotely therefrom.

FIG. 7 shows a sectional view along sixth plane 412 from FIG. 4B ofrobotic mechanical digit 100 in the straight or neutral pose. Visible inFIG. 7 are a back of the right cylinder 702 a, a right piston 704 aslideably received by the right cylinder 702 a for translation along afirst translation axis, a set of right O-Ring seals 706 a, the rightpiston rod 106 a directly coupled at a first end to right piston 704 aby a first right spherical or ball joint 708 a and at a second end tothe right pitch-yaw linkage 108 a by a second right spherical or balljoint 710 a, a right spring 712 a which sits within the right cylinder104 a and pushes on the right piston 704 a, a back of the left cylinder702 b, a left piston 704 b slideably received by the left cylinder 702 bfor translation along a second translation axis, a set of left O-Ringseals 706 b, the left piston rod 106 b directly coupled at a first endto the left piston 704 b by a first left spherical or ball joint 708 band at a second end to the left pitch-yaw linkage 108 b by a second leftor ball spherical joint 710 b, and a left spring 712 b which sits withinthe left cylinder 104 b and pushes on the left piston 704 b. Due to thespherical or ball joints on both sides of each of the right and leftpiston rods 106 a, 106 b, this actuation is capable of proceedingregardless of the rotation of the yaw carriage 110 around the z-axis.While illustrated using a spring 712 a, 712 b, some implementations mayhave ports to provide pressurized fluid at both a front and the back ofthe right and/or left cylinders 702 a, 702 b, allowing omission of thespring, but somewhat complicating the overall structure and operation.The ports may each have one or more valves associated therewith, forinstance active valves that can be operated to selectively pass or blocka passage of fluid therethrough, and/or passive valves, for instancecheck valves. The valve(s) may be positioned at the port(s) or remotelytherefrom.

FIG. 8 shows the sectional view along sixth plane 412 from FIG. 7 withportions of robotic mechanical digit 100 rotated counterclockwise abouta yaw (or “z”) axis. This pose is actuated by a right fluid movement 802(illustrated by a thick black arrow) moving from an external fluidreservoir through right fluid port 210 a and into the back of the rightcylinder 702 a, and a left fluid movement 804 (illustrated by a thickblack arrow) being expelled to an external fluid reservoir through leftfluid port 210 b. Fluid movements 802 and 804 cause equal but oppositemovements of the left and right pistons 704 a and 704 b causing arotation of the yaw carriage 110 (and the attached robotic digit) aroundthe pin joint 206. The external fluid reservoir may comprise a source offluid (e.g., liquid; gas), which may be pressurized, for instance via acompressor. One or more valves can be operated to control a flow, anddirection of flow, of fluids.

FIGS. 9A, 9B, and 9C show respective sectional views along fifth plane410 from FIG. 4A of various configurations of robotic mechanical digit100. In FIG. 9A, robotic mechanical digit 100 is in a neutral pose, forinstance at a neutral or default rotational position about a pitch axes.In FIG. 9B, robotic mechanical digit 100 is in a pitched-up pose, forinstance rotated counterclockwise about the pitch axis in relation tothe view of FIG. 9B. In FIG. 9C, the robotic mechanical digit 100 is ina pitched-down pose, for instance rotated clockwise about the pitch axisin relation to the view of FIG. 9C.

FIGS. 9A, 9B, and 9C also illustrate a left bleed port 902 b, a firstleft connective strip 904 b of the flexPCB 118 that travels between afirst left flexPCB rolling surface 906 a and a second left flexPCBrolling surface 906 b.

As noted, robotic mechanical digit 100 is illustrated in a pitched-uppose in FIG. 9B relative to the neutral pose illustrated in FIG. 9A. Theupward pitch results from (a) a fluid movement 908 out of the back ofthe left cylinder 702 b through the left fluid port 210 b, causing theleft piston 704 b to be pulled backwards (and/or pushed backwards byspring 712 b) in a negative direction along the y-axis, which, due tothe spherical or ball joints 708 b, 710 b coupling the left piston 704 bto the left pitch-yaw linkage 108 b, rotates the left pitch-yaw linkage108 b around pin joint 514 a which in turn causes the orbit of the firstphalanx 112 around the pin joint 514 a and (b) an identical fluidmovement in the right cylinder (not shown in FIG. 9B).

Also as noted, robotic mechanical digit 100 is illustrated in apitched-down pose in FIG. 9C relative to the neutral pose illustrated inFIG. 9A. The downward pitch results from (a) a fluid movement 910 intothe back of the left cylinder 702 b through the left fluid port 210 b,causing the left piston 704 b to be pushed forwards in a positivedirection along the y-axis, which, due to the spherical or ball joints708 b, 710 b coupling the left piston 704 b to the left pitch-yawlinkage 108 b, rotates the left pitch-yaw linkage 108 b around pin joint514 a which in turn causes the orbit of the first phalanx 112 around thepin joint 514 a and (b) an identical fluid movement in the rightcylinder (not shown in FIG. 9C).

As illustrated in FIGS. 9A, 9B, and 9C, the first left connective strip904 b travels between the yaw carriage 110 and the first phalanx 112 byextending between the first left flexPCB rolling surface 906 a and thesecond left flexPCB rolling surface 906 b, and transferring from one tothe other through the change in pose. The first left connective strip904 b may be made of an easily bendable material, although notnecessarily stretchable, for instance polyimide. The geometries and/orsurface curvatures of the rolling surfaces 906 a, 906 b are compatiblydesigned such that there is no length change in the path the first leftconnective strip 904 b takes when the first phalanx 112 shifts into andbetween the neutral pose of FIG. 9A, the pitched-up pose of FIG. 9B, andthe pitched-down pose of FIG. 9C. Thus, the first left connective strip904 b advantageously does not experience any high longitudinal stressthat may cause damage to the strip 904 b, and only experiences a bendingstress, which the bendable nature of the connective strip 904 b isgenerally more able to accommodate without breaking.

FIG. 10A shows a robotic mechanical digit 1000 in a straight or neutralpose and without a membrane or artificial skin in accordance with thepresent systems, devices, and methods. Mechanical digit 1000 of FIG. 10Ais substantially similar to mechanical digit 100 with the flexPCB 118removed or omitted.

FIG. 10B shows a first side 1001 a of a flattened flexPCB 1001 that maybe used, for example, as flexPCB 118 in mechanical digit 100. FIG. 10Cshows a second side 1001 b of the flattened flexPCB 1001 of FIG. 10A,the second side opposite the first side. The flexPCB 1001 can attach toand be routed through the various pieces of mechanical digit 1000 toproduce robotic mechanical digit 100, such as the flexPCB 118.

The flexPCB 1001 comprises the following, as shown in FIGS. 10B and 10C:a set of connective strips (collectively 904) comprising a first rightconnective strip 904 a, a first left connective strip 904 b, a secondright connective strip 904 c, a second left connective strip 904 d, athird right connective strip 904 e, and a third left connective strip904 f. The first left and right connective strips 904 a and 904 b eachconnect (e.g., physically couple) at a first end of a first phalanxpanel or wing 1002; the second left and right connective strips 904 cand 904 d each connect (e.g., physically couple) at and between a secondend of the first phalanx panel or wing 1002 and a first end of a secondphalanx panel or wing 1004; and the third left and right connectivestrips 904 e and 904 f each connect (e.g., physically couple) at andbetween a second end of the second phalanx panel or wing 1004 and afirst end of a third phalanx panel or wing 1006. The connective strips904 all carry power and communicative electrical lines to/from/betweenthe various panels or wings 1002, 1004, 1006. Each of the phalanx panelsor wings 1002, 1004, 1006 comprises a respective set of sub panels orsub-wings that, when folded around the edges of their respective digitphalanx (e.g., 112, 114, 116), cover the majority of the externalsurface area of the phalanx. Each of the phalanx panels or wings 1002,1004, 1006 carries a plurality of tactile, force, or pressure sensors1008 (only a few of which are indicated in the figures to reduceclutter). These sensors 1008 may be of a variety of sizes to achievedifferent tactile sensor densities at different parts of the digit 1000.Due to the fact that the connective strips 904 move through theinter-phalanx joints (as described in previous figures), the placementof the sensors 1008 alternates between the first side 1001 a and thesecond side 1001 b in order to always be pointing outwards on thesurface of the digit 1000. The plurality of sensors 1008 electricallycouple (optionally through an integrated circuit or microcontroller) tothe electrical lines carried by the connective strips 904, whichterminate at a set of connector pads 1010 a and 1010 b on which sit aset of mechanical and electrical couplers 1012 a and 1012 brespectively.

FIG. 11A shows robotic mechanical digit 100 in a pitched-down poseactuated by an extension (outward travel from a neutral position) ofboth the right and left pistons 106 a, 106 b in accordance with thepresent systems, devices, and methods. FIG. 11B shows robotic mechanicaldigit 100 in a pitched-up pose actuated by a retraction (inward travelfrom a neutral position) of the both right and left pistons 106 a, 106 bin accordance with the present systems, devices, and methods. Rotationabout the pitch axis without rotation about the yaw axis is actuated byconcurrent movements of the right piston 106 a along its translationaxis and the left piston 106 b along its translation axis that are equalin speed, magnitude and direction with respect to one another alongtheir respective translation axes. Conversely, rotation about the yawaxis with a rotation about the pitch axis is actuated by movements ofright piston 106 a along its translation axis and left piston 106 balong its translation axis that are at least one of: not concurrent, notmatched in speed, or not matched in magnitude, along their respectivetranslation axes.

FIG. 12A shows robotic mechanical digit 100 in a yaw-right pose actuatedby an extension (outward travel from a neutral position) of the leftpiston 106 b and a retraction (inward travel from a neutral position) ofthe right piston 106 a in accordance with the present systems, devices,and methods. FIG. 12B shows robotic mechanical digit 100 in a yaw-leftpose actuated by an extension (outward travel from a neutral position)of the right piston 106 a and a retraction (inward travel from a neutralposition) of the left piston 106 b in accordance with the presentsystems, devices, and methods. Rotation about the yaw axis withoutrotation about the pitch axis is actuated by concurrent movements of theright piston 106 a along its translation axis and the left piston 106 balong its translation axis that are equal in speed and magnitude butopposite in direction with respect to one another along their respectivetranslation axes.

FIG. 12C shows robotic mechanical digit 100 in a curled pose actuated byan extension (outward travel from a neutral position) of the bottompiston 604 in accordance with the present systems, devices, and methods.

FIG. 13A shows a first portion of robotic mechanical digit 100; FIG. 13Bshows a second portion of robotic mechanical digit 100.

As illustrated in FIGS. 13A and 13B, the first right connection strip904 a couples mechanically and electrically through the connector pad1010 a to a right yaw carriage PCB 1302 a which extends around the yawcarriage 110 through a connection strip 1308 to a left yaw carriage PCB,not visible in the figures but similar in design to the right yawcarriage PCB 1302 a and coupling to the first left connection strip 904b. Also coupled to the right yaw carriage PCB 1302 a is a yaw slackstrip 1306 through a connector pad 1304. The yaw slack strip 1306carries power and communication for the flexPCB 118 and is sufficientlyflexible to not break through the yaw motion of the yaw carriage 110.The yaw slack strip 1306 terminates at the electrical connector port202, visible in FIG. 2.

FIG. 14 shows a robotic mechanical hand 1400 comprised of a set of four(4) robotic mechanical digits in the form of mechanical fingers 1402,1404, 1406, and 1408 coupled to a palm 1410. The robotic mechanical hand1400 may also comprise a fifth mechanical digit in the form of a roboticmechanical thumb 1412 also coupled to the palm 1410. The roboticmechanical thumb 1412 may be positioned and operable to be opposed toone or more of mechanical fingers 1402, 1404, 1406, and 1408 to allow apinching or grasping pose to be realized. The set of four roboticmechanical fingers may be of different sizes or of the same size as oneanother. There may be more or fewer such robotic mechanical fingerscoupled to the palm 1410 to form such a robotic mechanical hand 1400.Any or all of robotic mechanical fingers 1402, 1404, 1406, and/or 1408may be substantially similar to mechanical digit 100 as describedthroughout the present systems, devices, and methods.

While the embodiments illustrated and described in the above descriptioncomprise gear systems, linkages, and hydraulic pistons, these subsystemsmay be replaced by cables, compliant mechanisms, and/or rolling membranepistons without significant changes to the operations and functionalityof the embodiments, as those skilled in the relevant art will recognize.

The above description of illustrated embodiments, including what isdescribed in the Abstract, is not intended to be exhaustive or to limitthe embodiments to the precise forms disclosed. Although specificembodiments of and examples are described herein for illustrativepurposes, various equivalent modifications can be made without departingfrom the spirit and scope of the disclosure, as will be recognized bythose skilled in the relevant art.

For instance, the foregoing detailed description has set forth variousembodiments of the devices and/or processes via the use of blockdiagrams, schematics, and examples. Insofar as such block diagrams,schematics, and examples contain one or more functions and/oroperations, it will be understood by those skilled in the art that eachfunction and/or operation within such block diagrams, flowcharts, orexamples can be implemented, individually and/or collectively, by a widerange of hardware, software, firmware, or virtually any combinationthereof. In one embodiment, the present subject matter may beimplemented via Application Specific Integrated Circuits (ASICs).However, those skilled in the art will recognize that the embodimentsdisclosed herein, in whole or in part, can be equivalently implementedin standard integrated circuits, as one or more computer programsrunning on one or more computers (e.g., as one or more programs runningon one or more computer systems), as one or more programs running on oneor more controllers (e.g., microcontrollers) as one or more programsrunning on one or more processors (e.g., microprocessors), as firmware,or as virtually any combination thereof, and that designing thecircuitry and/or writing the code for the software and or firmware wouldbe well within the skill of one of ordinary skill in the art in light ofthis disclosure.

In addition, those skilled in the art will appreciate that controlmechanisms taught herein for controlling a robotic member are capable ofbeing distributed as a program product in a variety of forms, and thatan illustrative embodiment applies equally regardless of the particulartype of signal bearing media used to actually carry out thedistribution. Examples of signal bearing media include, but are notlimited to, the following: recordable type media such as floppy disks,hard disk drives, CD ROMs, digital tape, and computer memory; andtransmission type media such as digital and analog communication linksusing TDM or IP based communication links (e.g., packet links).

The various embodiments described above can be combined to providefurther embodiments. To the extent that they are not inconsistent withthe specific teachings and definitions herein, all of the U.S. patents,U.S. patent application publications, U.S. patent applications, foreignpatents, foreign patent applications and non-patent publicationsreferred to in this specification and/or listed in the Application DataSheet, including but not limited to U.S. patent application Ser. No.62/937,044 and US provisional patent application Ser. No. 63/086,258,with the present disclosure are incorporated herein by reference, intheir entirety. Aspects of the embodiments can be modified, ifnecessary, to employ systems, circuits and concepts of the variouspatents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. A robotic end effector comprising: a first mechanical digitcomprising: a first base; a first phalanx; a first rolling surface jointthat rotationally mechanically couples the first phalanx to the firstbase for rotation about a pitch axis and rotation about a yaw axis; asecond phalanx; a second rolling surface joint that rotationallymechanically couples the second phalanx to the first phalanx forrotation about a first curl axis; a third phalanx; and a third rollingsurface joint that rotationally mechanically couples the third phalanxto the second phalanx for rotation about a second curl axis; a firstcylinder; a first piston slideably received by the first cylinder fortranslation along a first translation axis; a first linkage thatmechanically couples the first piston with the first phalanx at aposition laterally spaced on a first side of a centerline of the firstphalanx; a second cylinder; a second piston slideably received by thesecond cylinder for translation along a second translation axis; asecond linkage that mechanically couples the second piston with thefirst phalanx at a position laterally spaced on a second side of thecenterline of the first phalanx; a third cylinder; a third pistonslideably received by the third cylinder for translation along a thirdtranslation axis; and a third linkage that mechanically couples thethird piston with the second and the third phalanges, wherein therotation about the pitch axis is actuated by movement of both the firstpiston along the first translation axis and the second piston along thesecond translation axis, the rotation about the yaw axis is actuated bymovement of one or both of the first piston along the first translationaxis and the second piston along the second translation axis, and therotation about the first and the second curl axes is actuated bymovement of the third piston along the third translation axis.
 2. Therobotic end effector of claim 1 wherein a rotation about the yaw axiswithout rotation about the pitch axis is actuated by concurrentmovements of the first piston along the first translation axis and thesecond piston along the second translation axis that are equal in speedand magnitude but opposite in direction with respect to one anotheralong the respective first and second translation axes.
 3. The roboticend effector of claim 2 wherein a rotation about the pitch axis withoutrotation about the yaw axis is actuated by concurrent movements of thefirst piston along the first translation axis and the second pistonalong the second translation axis that are equal in speed, magnitude anddirection with respect to one another along the respective first andsecond translation axes.
 4. The robotic end effector of claim 1 whereina rotation about the yaw axis with a rotation about the pitch axis isactuated by movements of the first piston along the first translationaxis and the second piston along the second translation axis that are atleast one of: not concurrent, not matched in speed, or not matched inmagnitude, along the respective first and second translation axes. 5.The robotic end effector of claim 1 wherein the second translation axisis parallel to the first translation axis, and the yaw axis isperpendicular to a plane in which the first and the second translationaxes lie.
 6. The robotic end effector of claim 1 wherein the firstlinkage comprises a first piston rod having a first end and a secondend, the first end of the first piston rod coupled to the first pistonto rotate about two axes that are orthogonal to the first translationaxis, and the second linkage comprises a second piston rod having afirst end and a second end, the first end of the second piston rodcoupled to the second piston to rotate about two axes that areorthogonal to the second translation axis.
 7. The robotic end effectorof claim 6 wherein the first end of the first piston rod comprises afirst ball joint that is directly coupled to the first piston to rotateabout the two axes that are orthogonal to the first translation axis,and the first end of the second piston rod comprises a second ball jointthat is directly coupled to the second piston to rotate about the twoaxes that are orthogonal to the second translation axis.
 8. The roboticend effector of claim 6 wherein the second end of the first piston rodis coupled to the first phalanx to rotate about two axes that areorthogonal to the first phalanx, and the second end of the second pistonrod is coupled to the first phalanx to rotate about two axes that areorthogonal to the first phalanx.
 9. The robotic end effector of claim 6,further comprising: a first spring positioned to bias the first pistontoward a first piston position in the first cylinder; a first valvepositioned and operable to selectively open and close a first fluidlycommunicative path between a portion of an interior of the firstcylinder and a source of a pressurized fluid; a second spring positionedto bias the second piston toward a second piston position in the secondcylinder; and a second valve positioned and operable to selectively openand close a second fluidly communicative path between a portion of aninterior of the second cylinder and a source of a pressurized fluid. 10.The robotic end effector of claim 1 wherein the third linkage comprisesa third piston rod, a first set of gears coupled between the first baseand the first phalanx, a second set of gears coupled between the firstphalanx and the second phalanx, and a third set of gears coupled betweenthe second phalanx and the third phalanx.
 11. The robotic end effectorof claim 10 wherein the third piston rod has a first end and a secondend, the first end of the third piston rod coupled to the third pistonto translate therewith, and the second end of the third piston rodrotatably coupled to at least one gear of the first set of gears, atleast one of the gears of the first set of gears coupled to at least oneof the gears of the second set of gears, and at least one of the gearsof the second set of gears coupled to at least one gear of the third setof gears to transfer translational movement of the third piston rod intorotational movement of the second and the third phalanges about thefirst and the second curl axes, respectively.
 12. The robotic endeffector of claim 11 wherein the third linkage further comprises aplurality of bar links that couple at least one gear from the first setof gears to at least one gear of the second set of gears and that coupleat least one gear from the second set of gears to at least one gear ofthe third set of gears.
 13. The robotic end effector of claim 11 whereinthe first end of the third piston rod comprises a ball joint that isdirectly coupled to the third piston to rotate about two axes that areorthogonal to the third translation axis.
 14. The robotic end effectorof claim 11 wherein the second end of the third piston rod is coupled torotate about an axis that is parallel to the pitch axis and to rotateabout an axis that is parallel to the yaw axis.
 15. The robotic endeffector of claim 10, further comprising: a third spring positioned tobias the third piston toward a third piston position in the thirdcylinder; and a third valve positioned and operable to selectively openand close a third fluidly communicative path between a portion of aninterior of the third cylinder and a source of a pressurized fluid. 16.The robotic end effector of claim 10, further comprising: a flexibleprinted circuit board that extends between the first base and the thirdphalanx and which wraps partially about each of the first rollingsurface joint, the second rolling surface joint, and the third rollingsurface joint.
 17. The robotic end effector of claim 16 wherein: thefirst rolling surface joint comprises a first rolling surface of thefirst base and a second rolling surface of the first phalanx; theflexible printed surface board extends over the first rolling surface ofthe first base and the second rolling surface of the first phalanx; andrespective surface curvatures of the first rolling surface of the firstbase and the second rolling surface of the first phalanx arerespectively shaped relative to the pitch axis to ensure there is nolength change in a path of the flexible printed circuit board when thefirst phalanx transitions into and between a neutral pose, a pitched-uppose, and a pitched-down pose.
 18. The robotic end effector of claim 1wherein the first cylinder, the second cylinder, and the third cylinderare all formed in the first base.
 19. The robotic end effector of claim18 wherein the first base comprises a fluid manifold including: a volumethat contains at least respective portions of each of the firstcylinder, the second cylinder, and the third cylinder; a first valvepositioned and operable to selectively open and close a first fluidlycommunicative path between a portion of an interior of the firstcylinder and a source of a pressurized fluid; a second valve positionedand operable to selectively open and close a second fluidlycommunicative path between a portion of an interior of the secondcylinder and a source of a pressurized fluid; and a third valvepositioned and operable to selectively open and close a third fluidlycommunicative path between a portion of an interior of the thirdcylinder and a source of a pressurized fluid.
 20. The robotic endeffector of claim 1, further comprising: a palm, wherein the first baseis mechanically coupled to or part of the palm; and a second mechanicaldigit comprising: a second base mechanically coupled to or part of thepalm; a fourth phalanx; a fourth rolling surface joint that rotationallymechanically couples the fourth phalanx to the second base for rotationabout a pitch axis and rotation about a yaw axis; a fifth phalanx; afifth rolling surface joint that rotationally mechanically couples thefifth phalanx to the fourth phalanx for rotation about a third curlaxis; a sixth phalanx; and a sixth rolling surface joint thatrotationally mechanically couples the sixth phalanx to the fifth phalanxfor rotation about a fourth curl axis; a fourth cylinder; a fourthpiston slideably received by the fourth cylinder for translation along afourth translation axis; a fourth linkage that mechanically couples thefourth piston with the fourth phalanx at a position laterally spaced ona first side of a centerline of the fourth phalanx; a fifth cylinder; afifth piston slideably received by the fifth cylinder for translationalong a fifth translation axis; a fifth linkage that mechanicallycouples the fifth piston with the fourth phalanx at a position laterallyspaced on a second side of the centerline of the fourth phalanx; a sixthcylinder; a sixth piston slideably received by the sixth cylinder fortranslation along a sixth translation axis; and a sixth linkage thatmechanically couples the sixth piston with the fifth phalanx and thesixth phalanx, wherein the rotation about the pitch axis is actuated bymovement of both the fourth piston along the fourth translation axis andthe fifth piston along the fifth translation axis, the rotation aboutthe yaw axis is actuated by movement of one or both of the fourth pistonalong the fourth translation axis and fifth piston along the fifthtranslation axis, and rotation about the third and the fourth curl axesis actuated by movement of the sixth piston along the sixth translationaxis.